The question about roll bars and shoulder harnesses has been discussed here recently.
The issue is not whether they can be installed but whether it is wise to do so.
Shelby American WILL NOT INSTALL HARNESSES ON THE PASSENGER SIDE DUE TO SAFETY REASONS. It's all about whether you want your passenger to be the roll bar if there isn't one installed.
See here:
Advice on Mounting my Should Harness for SPF #205
And particularly response #9.
I will tell you that when I ride in a Cobra with passenger side harnesses and no roll bar I do not use them.